Do-more H2 Series PLC Hardware User Manual, 1st Edition, Rev. F - H2-DM-M
4–6
Chapter 4: Specifications - Base Units
1
2
3
4
5
6
7
8
9
10
11
12
13
14
A
B
C
D
Power Budget
When determining the types and quantity of I/O modules you will be using, it is important
to remember there is a defined amount of power available from the base power supply. The
charts on the next page indicates the power supplied and used by each module. The chart
below shows an example of how to calculate the power used by your particular system. These
charts should make it easy for you to determine if the devices you have chosen will operate
within the power budget of your system configuration. If the I/O you have chosen exceeds
the maximum power available from the power supply, you may be able to resolve the problem
by using remote I/O bases.
Power Budget Example
The example below shows how to calculate the power budget for the Do-more PLC system. The
examples are constructed around a single 9-slot base using the devices shown. It is recommended
that you construct a similar table for your Do-more PLC system. Follow the following steps to
determine your power budget.
1. Using a chart similar to the one below, fill in column 2.
2. Using the tables on the next page, enter the current supplied and used by each device (columns 3
and 4). Devices which fall into the “Other” category (Row D) are devices such as the C-more Micro
interface, which also have power requirements, but do not directly plug into the base.
3. Add the current used by the system devices (columns 3 and 4) starting with the CPU slot and put
the total in the row labeled “Maximum Current Required” (Row E).
4. Subtract the row labeled “Maximum Current Required” (Row E), from the row labeled “Current
Supplied” (Row B). Place the difference in the row labeled “Remaining Current Available” (Row F).
5. If “Maximum Current Required” is greater than “Current Supplied” in either column 3 or 4, the
power budget will be exceeded. It will be unsafe to use this configuration, and you will need to
restructure your I/O configuration. Note the auxiliary power supply does not need to supply all the
external power. If you need more than the 300mA supplied, you can add an external 24V power
supply. This will help keep you within your power budget for external power.
A
Column 1
Column 2
Column 3
Column 4
Device Type
5VDC (mA)
External Power 24 VDC (mA)
B
CURRENT SUPPLIED
Base
9 slot
2,600
300
C
CURRENT REQUIRED
CPU SLOT
SLOT 0
SLOT 1
SLOT 2
SLOT 3
SLOT 4
SLOT 5
SLOT 6
SLOT 7
H2-DM1E
D2-16ND3-2
D2-16ND3-2
D2-16NA
D2-08NA-1
D2-16TD1-2
D2-08TA
D2-08TA
275
100
100
100
50
200
250
250
0
0
0
0
0
80
0
0
D
OTHER
Operator interface
EA1-S3ML
90
0
E
Maximum Current Required
1415
80
F
Remaining Current Available
2600-1415=1185
300-80=220
